Upgrading PHP version used by composer, dependency

Strange, php -v outputs:

PHP 7.4.14 (cli) (built: Jan  5 2021 14:30:27) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
    with Zend OPcache v7.4.14, Copyright (c), by Zend Technologies

just cut paste vendor directory to somewhere else in case you need them. then try to run

 composer update && composer install

if you not made any changes in vendor it's safe to remove that but let it leave. do one thing make a new folder somewhere outside of your project & copy all files except node_modules & vendor.

there you can can do experiments your app will untouched , if everything fine you can make changes in your app. use git to avoid any accident.

however ^7.3 is ok, i am running production app which env is 7.4.X.

Removing both of these folders bring up other issues like Laravel not finding some files and whatnot, unaware of the approach, could you be more specific like whats the intention of it? By removing and then running composer install && composer update, how would it impact the version used by Composer for my dependencies? Thanks.

EDIT: I mean I can understand this will reinstall composer and will update it, but how can I tell it to install a specific version? Inside composer.lock I see that there's a platform variable with a prefixed version of PHP, as you can understand it's been a while without success and I have a lot of questions.

everything seams correct so my first approach was there any package which has php 7.3 dependency. but i was wrong , problem is inside composer installation. i thought you have only php version on your computer so first thing if not needed remove all them except 7.4. then remove and reinstall composer make sure to remove composer configs from ($HOME/.composer/vendor/bin).

And please provide some info about your dev env.
like your installation type is native or comes with any package like lamp,xammp ,wamp etc. 

and answer of your question is you can but it's not good idea to make changes in composer-lock.json because with every update it changes.

Hello @jlrdw can you say which path does Composer usually reaches for php? Im on a Mac. I found, by running which php a path that outputted this: /usr/local/bin/php this file has 7.4 version of PHP. Let's say I want to use this path, how would I go about redirecting Composer? Thanks :-)

Theres a GUI for Windows on Composer?

Just a GUI installer.

Also see https://getcomposer.org/doc/00-intro.md#installation-linux-unix-macos

You may want to delete (uninstall all php) then install the one version you want. I normally have only one php installed. I currently have ver 8. But remember for projects built with 7.* you may need some small code changes.

View the what's new in php 8 series on laracasts.

Edit: I had wrong title, see https://laracasts.com/series/php8-crash-course

Does he go around installing Composer's version for dependencies? Yea, I could love a PHP course right now :-) I havent been able to figure out how to redirect Composer yet. Hope it doesn't take me too long.

Edit: I think im using Laravel 8, what's one way of figuring that out?

By the way @jlrdw , the platform version in composer.lock , is the one used for all dependencies? Is that what you mean by installing composer again? I mean I've tried resetting that number and running composer install, could I change the settings for that file? I can also try this but don't know how convenient would be: https://php.watch/articles/composer-ignore-platform-req

I wasn't referring to laravel here, composer install is for installing the framework.

What I meant, is when I install a new php version, I also reinstall composer and point it to my php.exe file.

Laravel has nothing to do with a new composer install.

Are you saying you need several versions of php on your system?

Edit: Sorry if I am misunderstanding something.

I want to use a package that requires 7.4 of PHP.

For multiple versions, I found this:

https://laracasts.com/discuss/channels/laravel/run-composer-commands-with-different-php-versions

If that don't help maybe Google:

Using composer for various php versions.

Something like that. I only have one version at a time. If all you have is 7.4 you are good to go.

Do you know where the .bash_aliases is located? I can see .bash_profile, according to an answer in StackOverflow, (produced by the URL you provided) I could make an alias for Composer and in that way resolve that issue of redirecting Composer, but I don't know where that is. Anyway what I found on .bash_profile is interesting:

alias composer733='/c/[xampp folder]/php733/php.exe /c/ProgramData/ComposerSetup/bin/composer.phar '. .bash_profile

But that path seems to be of a Windows OS machine. However it checks with what the answer is suggesting, there's an alias, and the version used there seems to be of a 7.3 PHP. I ran brew search phpand various versions came out:

==> Formulae
brew-php-switcher   php-cs-fixer        [email protected] ✔           phpmyadmin
php ✔               [email protected] ✔           phplint             phpstan
php-code-sniffer    [email protected] ✔           phpmd               phpunit

3 versions are checked, im guessing those are the ones installed on my Macbook?

Damn! This is much much much harder than I thought. composer -vvv about 2>&1 | grep "PHP" says it's

Running 2.0.9 (2021-01-27 16:09:27) with PHP 7.4.14 on Darwin / 19.6.0
Composer - Dependency Manager for PHP

And phpinfo() outputs PHP Version 7.3.25

Have you fixed the issue? I guess the problem is with the web server you are using